Abstract

Vehicular bumper is a structure mounted at the front and rear of the vehicle to absorb the first impact and is designed to minimize its effect on the vehicle structure and its occupants. Although vehicle collision is an unavoidable fact, there are no reported attempts to date in exploring the feasibility of detection system utilizing sensors. For this investigation, PVDF (Polyvinylidene Fluoride) sensor for its sensitivity and dynamic range is selected for application to bumpers. A prototype bumper with PVDF sensors is fabricated to carry out tests under low level forces. A prototype bumper represented by a Plexiglass beam is mounted with a series of PVDF sensors across the length, while the bumper is mounted on a rigid structure through set of mounts. Each sensor is calibrated for various loads on and away from the sensor and tested to predict the magnitude of the force and corresponding position. Several configurations for the bumper with and without cover over the sensor surface are experimented to determine the collision detection capability of the bumper in terms of magnitude, duration and location of the impact. The time history response of each sensor and its characteristics are utilized to develop layouts for bumper systems with sensors. Two designs were fabricated and tested in the laboratory to establish methodology for establishing relationships between sensor responses with magnitude and location of collision. Based on the investigation, a final design is proposed for implementation of collision detection in automotive bumpers.